Glycemic index, retinal vascular caliber, and stroke mortality.
OBJECTIVE
It is unclear whether diets with high glycemic index (GI) and low cereal fiber (CF) are associated with greater risk of stroke. We aimed to assess the relationship between dietary GI and CF content, retinal microvasculature changes, and stroke-related mortality.


METHODS
The study consisted of a population-based cohort, 49+ years, examined at baseline (1992 to 1994). At baseline, participants completed validated food frequency questionnaires. Mean GI was calculated using an Australian database. Retinal arteriolar and venular diameters were measured from photographs. Mortality data were derived using the Australian National Death Index.


RESULTS
Over 13 years, 95 of 2897 participants (3.5%) died from stroke. Increasing GI (hazard ratio, 1.91; 95% CI, 1.01 to 3.47, highest versus lowest tertile) and decreasing CF (hazard ratio, 2.13; 95% CI, 1.19 to 3.80, lowest versus highest tertile) predicted greater risk of stroke death adjusting for multiple stroke risk factors. Persons consuming food in the highest GI tertile and lowest CF tertile had a 5-fold increased risk of stroke death (hazard ratio, 5.06; 95% CI, 1.67 to 15.22). Increasing GI and decreasing CF were also associated with retinal venular caliber widening (P(trend)<0.01). Adjustment for retinal venular caliber attenuated stroke death risk associated with high GI by 50% but did not affect the risk associated with low CF consumption.


CONCLUSIONS
High-GI and low-CF diets predict greater stroke mortality and wider retinal venular caliber. The association between a high-GI diet and stroke death was partly explained by GI effects on retinal venular caliber, suggesting that a high-GI diet may produce deleterious anatomic changes in the microvasculature.
Kaushik
Shweta
S
Centre for Vision Research, Department of Ophthalmology, Westmead Millennium Institute, University of Sydney, Westmead Hospital, Hawkesbury Road, Westmead, NSW Australia.
Wang
Jie Jin
JJ
Wong
Tien Y
TY
Flood
Victoria
V
Barclay
Alan
A
Brand-Miller
Jennie
J
Mitchell
Paul
P
D000368:Aged; D001315:Australia / Q000453:epidemiology; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology; D003930:Diabetic Retinopathy / Q000097:blood / Q000453:epidemiology* / Q000503:physiopathology; D004040:Dietary Carbohydrates / Q000009:adverse effects* / Q000097:blood; D005260:Female; D005526:Food, Formulated / Q000009:adverse effects*; D038321:Glycemic Index / Q000502:physiology*; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000453:epidemiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D016016:Proportional Hazards Models; D012161:Retinal Artery / Q000473:pathology / Q000503:physiopathology; D012169:Retinal Vein / Q000473:pathology / Q000503:physiopathology; D012307:Risk Factors; D020521:Stroke / Q000097:blood / Q000401:mortality* / Q000503:physiopathology; D011795:Surveys and Questionnaires
D004040:Dietary Carbohydrates